Herbert Strong, along with Tracy Hall, Francis Bundy, and Robert Wentorf, synthesized diamonds as part of Project Superpressure, as announced by the GE Research Laboratories in 1955. The group used high pressure, graphite, and a catalyst to achieve diamond chips suitable for industrial applications.
The four researchers knew that graphite, a pure carbon substance, was key to achieving manmade diamonds. They discovered, however, that graphite was resistant to change due to strong bonding of the carbon atoms. By utilizing iron sulfide as a catalyst to weaken the carbon bonds and by applying high pressure, they were able to turn the weakened graphite into manmade diamonds for the first time in December 1954.
Diamonds have a wide variety of applications because of their exceptional physical characteristics, including hardness and heat conductivity, making them ideal for use in cutting, grinding, and polishing. Today, over 100 tons or over 450 million carats of synthetic diamonds are produced annually for industrial use.
Strong joined the GE Research Lab in 1946 as a research associate. By the time of his retirement in 1973, he held 21 patents and had worked to synthesize carat-sized diamonds which found use in electronic equipment. He later worked with the Schenectady High School to develop a program called Fun with Physics to teach children about science.